The provision of liquid pharmaceuticals in a pre-filled syringe is desirable because it eliminates manipulations required to remove the product from a conventional ampule, vial or bottle and transfer it to a syringe prior to use. Conventional processes for final assembly and sealing of pre-filled syringes, however, require the development of pressure and/or a partial vacuum in order to effectively seat the elastomeric closures which seal the product within the syringe. In one typical process, the tooled end of a syringe (the reduced diameter end that typically receives the needle) is sealed and the product filled through the large opening at the opposite end of the syringe. A partial vacuum is applied to the open end and an elastomeric closure is inserted in the syringe. When the vacuum is vented, the closure is effectively positioned within the barrel of the syringe as a result of the differential pressure existing within the syringe. As is apparent, this process results in the development of a vacuum within the syringe barrel which is detrimental to a pressure or vacuum sensitive product. In another typical process, a syringe is filled as described above, but the elastomeric closure is inserted into the barrel of the syringe with a wire or guide beside the closure. After the closure is inserted to its selected location in the syringe, the wire or guide is withdrawn. This process avoids the use of vacuum to seat the closure in the syringe, but is cumbersome and not an efficient method for large-scale production.
An alternative process for filling syringes has been developed that does not involve the development of pressure or vacuum in the syringe. In this process the large diameter end of the syringe is sealed first in a conventional manner and the liquid product is introduced through the tooled end of the syringe. The tooled end is subsequently capped with a needle or plug. This process is not preferred because the filling speed of the product through the reduced diameter end is inadequate for efficient large scale manufacturing processes.
An apparatus was developed by Becton-Dickinson, Inc. (Franklin Lakes, N.J.) for use in introducing a second closure into a two-compartment vial or syringe. This apparatus was designed to insert a closure into a syringe to seal the second compartment in a manner that did not disturb the closure sealing the first compartment. This was accomplished without pulling a vacuum or developing a pressure. It was neither known nor suggested that the apparatus could be used for packaging and/or sealing a single compartment container containing a pressure or vacuum sensitive product.
It would be desirable, therefore, to provide a method for packaging and sealing single compartment containers containing a pressure or vacuum sensitive product. Heretofore, no such method has been developed or known to the industry.